This study is aimed at clarifying the relationship of certain respiratory variables to meditation, wakefulness, drowsiness, and sleep. Because respiration is under both voluntary and autonomic control, because it is tied to reticular activating system activity, and because it is a central part of meditative practices, a study of respiration will provide further information on the psychophysiology of meditation. In the present study, alveolar carbon dioxide tension, CO2 sensitivity of the respiratory centers, ventilation, and abdominalthoracic respiratory patterns are being measured and recorded, along with psychophysiologic measures indicative of level of wakefulness; i.e., EEG, EMG, and EOG. These recordings are made on meditators and non-meditating controls. This study includes three different meditative traditions, thus providing standardization of techniques for comparison across disciplines.